1. Field of the Invention
The present invention relates to a color image forming apparatus, a color image forming method, a color image forming program, and a recording medium.
2. Description of the Related Art
In an electrophotographic printer, out-of-color registration occurs if there is distortion of a lens or a mirror due variations in the internal temperature or deterioration with age. Therefore, there has been a method for forming an out-of-color registration detection pattern on a transfer belt at a predetermined timing, and reading the pattern by a sensor, thereby correcting out-of-color registration.
However, if an out-of-color registration correction operation is performed each time the change in the internal temperature is above a threshold, pattern formation or a detection operation must be executed each time the out-of-color registration correction operation is performed. This causes problems that a user cannot perform printing while the out-of-color registration correction operation is being performed, toner consumption increases in order to perform pattern formation, a load on a cleaning member that collects the toner used for forming the pattern increases, and waste toner collection capacity will have to be increased.
Japanese Patent Application Laid-open No. 2003-207976 discloses a technique in which a correspondence table of amounts of out-of-color registration with respect to temperatures is prepared in advance and an amount of out-of-color registration for the current internal temperature of a machine is determined from this correspondence table. In this technique, thus, it is possible to perform out-of-color registration without forming the out-of-color registration detection pattern.
However, in the above technique, because always the same amount of out-of-color registration is used, variations in the amount of out-of-color registration due to aging or machine-specific factors cannot be taken into account. As a result, the detection accuracy of out-of-color registration is not satisfactory.